JP2001071208A - Rotary grinding tool having super hard quality external-peripheral cutting edge - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotary diamond grinding tool obtaining high efficient and good accurate grinding performance. SOLUTION: In this rotary grinding tool 10, a plurality of super hard quality external peripheral cutting edges (columnar super hard member) 14 are secured with a prescribed space so as to protrude from an external peripheral part of a rotary unit 12 in a tilted condition relating to the diametric direction B so as to be toward the rotational direction A as going toward the trip end side, that is, the external peripheral side, so that a positive rake angle θs is formed in a side surface on the side of the rotational direction A in a tip end part of the super hard external peripheral blade (columnar super hard member) 14, consequently, accurate grinding is continuously performed in high efficiency. That is, even when the tip end part of the external peripheral cutting edge (super hard member) is worn, by preventing a change of its shape, a grinding condition is not changed to continuously obtain high efficient accurate grinding, also by eliminating retraction of a bond and coming off of an abrasive grain as compared with a grinding wheel connecting the abrasive grain by a bond, no scratch and chipping are generated, and a good grinding surface is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for projecting a plurality of columnar super-hard members made of diamond or CBN from the outer peripheral portion of a rotating body, and using the plurality of columnar super-hard members to achieve high precision and high efficiency. The present invention relates to a rotary grinding tool having a super-hard outer peripheral blade for performing precision grinding, super-finishing, lapping, and the like.

[0002]

2. Description of the Related Art In the field of metal precision processing such as precision grinding, super finishing and lapping performed in molds, bearings, hydraulic parts, etc., single crystals such as quartz, silicon, compound semiconductors such as gallium arsenide and gallium phosphide, In the field of non-metallic precision machining such as precision grinding and lapping performed on glass, ceramics, etc., it is necessary to machine to a so-called mirror surface level. For this purpose, for example, fine abrasive grains having a grain size of about # 2000 or more are fixed. It is common to use as abrasive grains or loose abrasive grains.

[0003]

By the way, in the field of precision machining as described above, there are many types of machining which use a grinding tool having abrasive grains having a large grain size and sequentially perform machining using a grinding tool having small abrasive grains. It is common to carry out stepwise processing. According to this, processing efficiency can be obtained as compared with the case of using fine abrasive grains from the beginning, but there is a disadvantage that the efficiency of precision processing cannot be sufficiently obtained because multi-step processing is required. . In addition, in precision processing of highly brittle materials such as single crystals, glass, and ceramics, chipping and scratching occur in the grinding processing, and post-processing such as lapping and polishing to remove them is required. However, there is a disadvantage that precision machining cannot be performed efficiently.

On the other hand, diamond abrasive grains or CB
Using a rotary grinding tool that combines N abrasive grains with a resin bond, metal bond, or vitrified bond, applying precise truing and dressing to the surface and using the same cutting edge height for the abrasive grains Grinding may be performed. However,
Such a rotary grinding tool shows high efficiency and good precision grinding performance in the initial stage of use, but the abrasive grain on the surface layer is worn or the bond recedes, so the sharpness is reduced, the abrasive grains fall off or crush. There is a drawback that scratching and chipping occur due to the above.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a rotary diamond grinding tool capable of obtaining high efficiency and good precision grinding performance.

The inventors of the present invention have conducted various studies to achieve the above object. As a result, a single-crystal or polycrystalline columnar diamond was formed so that its longitudinal direction was substantially radial and its surface on the rotational direction side was used. It has been found that when the rotary grinding tool is configured by fixing the rotary grinding tool to the outer peripheral portion of the rotating body in a state where it is inclined so as to form a positive rake angle, precision grinding is continuously performed with high efficiency. The present invention has been made based on such findings.

[0007]

That is, the gist of the rotary grinding tool having the super-hard outer peripheral edge of the present invention is that a plurality of columnar super-hard members made of diamond or CBN are rotated more toward the tip side. That is, they are fixed at predetermined intervals so as to protrude from the outer peripheral portion of the rotating body while being inclined in the direction.

[0008]

In this manner, the plurality of columnar super-hard members made of diamond or CBN are projected from the outer peripheral portion of the rotating body in such a state that the plurality of columnar super-hard members are inclined in the direction of rotation toward the tip end. Since they are fixed at intervals, a positive rake angle is formed on the side surface on the rotation direction side at the tip end of the columnar super-hard member, so that precision grinding is continuously performed with high efficiency. In other words, even if the tip of the columnar super-hard member wears, its shape does not change, so the grinding conditions do not change and high-precision precision grinding can be continuously obtained, and compared to a grinding wheel that combines abrasive grains with a bond Then, since there is no retreat of the bond and no drop of the abrasive grains, scratches and chipping do not occur, and a good ground surface can be obtained.

[0009]

In another preferred embodiment of the present invention, the tip end surface of the columnar hard member preferably has a positive clearance angle. With this configuration, a positive clearance angle is provided on the surface following the cutting edge on the rotation direction side of the tip end surface of the columnar hard member, so that the grinding resistance due to the cutting edge is reduced and the grinding load is reduced, There is an advantage that the grinding surface is further improved and the tool life is extended.

Preferably, the columnar hard member has a rectangular columnar shape having a rectangular cross section, and a cutting edge, which is one side of the rectangular tip surface on the rotation direction side, is formed in the grinding direction of the columnar hard member. Is fixed to the rotating body so as to be substantially orthogonal to the rotating body. With this configuration, the cutting edge is formed so as to be parallel to the machined surface of the workpiece, so that the grinding efficiency is further improved and the ground surface is improved.

[0011] Preferably, the columnar hard member is a diamond single crystal or a CBN single crystal, and a wear-resistant direction which is most resistant to wear in a tip end surface thereof is substantially parallel to a grinding direction of the columnar hard member. As described above. With this configuration, the wear of the distal end portion of the columnar hard member is suppressed, so that the durability of the rotary grinding tool can be further improved.

[0012]

Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

FIGS. 1 and 2 show a front view and a side view, respectively, of a rotary grinding tool 10 having a super-hard outer peripheral edge, which is partially cut away, according to an embodiment of the present invention. The rotary grinding tool 10 includes a steel disk-shaped metal base, that is, a rotating body 12.
And a plurality of super-hard outer peripheral blades 14 protruding from the outer peripheral surface of the rotating body 12 at a part on the distal end side. The super hard outer peripheral blade 14 is made of, for example, single crystal or polycrystalline diamond or CBN (Cubic Boron Nitride: cubic boron nitride) and has a Knoop hardness of 47 at room temperature.
3 or more, and has a columnar shape or a longitudinal shape having a rectangular cross-sectional shape as shown in FIG. The rotating body 12 is tilted with respect to the radial direction B.
Are fixed at equal intervals to the outer peripheral portion at predetermined intervals.

The super-hard outer peripheral blade 14 is formed such that one side of the rectangular end surface 16 in the direction of rotation A is parallel to the rotation axis C of the rotating body 12. It is arranged on the rotating body 12 so as to be substantially orthogonal to the grinding direction, that is, the rotation direction A,
The side constitutes the cutting edge 18 of the super-hard outer peripheral blade 14. The tip surface 16 of the super hard outer peripheral blade 14 is inclined at a predetermined angle with respect to the longitudinal direction, and the clearance angle θ _N of the leading surface 16 following the cutting edge 18 is substantially zero. The clearance angle θ _N is the angle of the tip surface 16, that is, the clearance surface with respect to the tangent line S passing through the cutting edge 18, and is defined as a positive clearance angle when the tip surface 16 is located on the inner peripheral side of the cutting edge 18. ing.

The super hard outer peripheral blade 14 is inclined with respect to the radial direction B of the rotating body 12 so that the rotating body 1 is inclined toward the rotating direction A toward the distal end side, that is, toward the outer peripheral side.
2, the side surface of the super hard outer peripheral blade 14 on the rotation direction A side (the side toward the rotation direction A) forms the rake face of the cutting edge 18 and forms a positive rake angle θ _S. ing. The rake angle θ _S is determined by the rotation axis C and the cutting edge 1.
8 is the angle formed by the rake face, which is the side face on the rotation direction A side of the super hard outer peripheral blade 14 with respect to the line in the radial direction B passing through 8.
As shown in FIG. 1, when the rake face is located on the opposite side of the cutting direction 18 in the rotation direction A, it is defined as a positive rake angle.

When the super-hard outer peripheral blade 14 is a diamond single crystal or a CBN single crystal, there is a wear resistant direction T which is most resistant to wear in the rectangular cross section. For this reason, the super hard outer peripheral blade 14 is fixed to the rotating body 12 so that the wear resistance direction T is substantially parallel to the grinding direction of the super hard outer peripheral blade 14, that is, the rotation direction A.

According to the rotary grinding tool 10 of the present embodiment configured as described above, the plurality of ultra-hard outer peripheral blades (columnar ultra-hard members) 14 made of diamond or CBN are directed toward the distal end, that is, the outer peripheral side. The outer peripheral edge of the super-hard outer blade (columnar super-hard member) 14 is fixed at a predetermined interval so as to protrude from the outer peripheral portion of the rotating body 12 in a state inclined toward the rotation direction A with respect to the radial direction B. Since a positive rake angle θ _S is formed on the side surface on the rotation direction A side at the tip end, precision grinding is continuously performed with high efficiency. That is, even if the tip of the super-hard outer peripheral blade (columnar super-hard member) 14 is worn, its shape does not change, so that grinding conditions are not changed and high-precision precision grinding can be continuously obtained. Compared with the grinding wheel combined with the above, since there is no retreat of the bond and no drop of the abrasive grains, scratches and chipping do not occur and a good ground surface can be obtained.

Further, according to the rotary grinding tool 10 of the present embodiment, the super-hard outer peripheral blade (column-shaped super-hard member) 14 has a rectangular cross-section having a rectangular cross section, and the rotation direction A of the tip surface 16 thereof. The cutting edge 18 which is one side of the super hard outer peripheral edge 1
Since the cutting edge 18 is fixed to the rotating body 12 so as to be substantially perpendicular to the grinding direction of 4, that is, the rotation direction A, the cutting edge 18 is formed so as to be parallel to the processing surface of the work material. Further, the grinding efficiency is improved and the grinding surface is improved.

Further, according to the rotary grinding tool 10 of the present embodiment, the super hard outer peripheral edge (columnar super hard member) 14 is a diamond single crystal or a CBN single crystal, and its tip surface 16
Of the super-hard outer peripheral blade 14 is fixed to the rotating body so that the wear-resistant direction T, which is most resistant to abrasion, is substantially parallel to the grinding direction of the super-hard outer peripheral blade 14, that is, the rotation direction A. Since the wear of the portion is suppressed, the durability of the rotary grinding tool 10 can be further improved.

Next, another embodiment of the present invention will be described. In the following description, the same parts as those in the above-described embodiment are denoted by the same reference numerals, and description thereof will be omitted.

The rotary grinding tool 20 shown in FIG. 4 is different from the above-mentioned embodiment in that it has a super-hard outer peripheral blade 22 having a tip end shape different from that of the super-hard outer peripheral blade 14 of the above-described embodiment. Have been. The distal end surface 24 of the super hard outer peripheral blade 22 of the present embodiment is further inclined than the aforementioned front end surface 16 of the super hard outer peripheral blade 14 so that a positive clearance angle θ _N is formed.

According to the rotary grinding tool 20 of this embodiment,
In addition to the same effect as the aforementioned embodiment can be obtained, so that the tip end face 24 of superhard peripheral cutting edge (columnar superhard member) 22 has a positive relief angle theta _N superhard peripheral cutting edge (columnar superhard Since the shape of the (member) 22 is set,
Since the flank following the cutting edge 26 formed on the rotation direction A side on the distal end surface 24 of the super-hard outer peripheral blade 22 has a positive clearance angle θ _N , the grinding resistance by the cutting edge 26 is reduced. There is an advantage that the grinding load is reduced, the grinding surface is further improved, and the tool life is extended.

FIGS. 5 and 6 are a front view and a side view, respectively, showing a part of a rotary grinding tool 30 according to another embodiment of the present invention. The rotary grinding tool 30 of the present embodiment is characterized in that, for example, the super-hard outer peripheral blade 14 is arranged in a plurality of rows on the outer peripheral surface of a thick disk-shaped rotary body 32. In the rotary grinding tool 30 of the present embodiment, three rows and four rows are alternately arranged at predetermined intervals in the circumferential direction in the width direction of the outer peripheral surface of the rotating body 32,
The super-hard outer peripheral blades 14 are arranged such that the rotation locus of the cutting edge 18 of the super-hard outer peripheral blade 14 in each row is a common cylindrical surface. According to the rotary grinding tool 30 of the present embodiment, the plurality of super-hard outer peripheral blades 14 are inclined in the direction of rotation A toward the distal end side in the same manner as in the embodiment of FIG. 32, a positive rake angle θ _S is formed on the side surface of the super-hard outer peripheral blade 14 on the rotation direction A side. The same effects as those of the rotary grinding tool 10 of the illustrated embodiment can be obtained. In addition, since the rotation trajectory of the cutting edge 18 of the super-hard outer peripheral blade 14 of the present embodiment forms a cylindrical surface having a large width (axial length), the width dimension that can be ground at the same time becomes large, so that And the efficiency of the grinding operation is improved.

FIGS. 7 and 8 are a front view and a partially cutaway side view showing a rotary grinding tool 40 according to another embodiment of the present invention. The rotary grinding tool 40 of the present embodiment has, for example, the above-mentioned super-hard peripheral blade 14 at an outer peripheral portion of one surface of the disk-shaped rotary body 42 at equal intervals along one circumference, similarly to a so-called cup-shaped grinding wheel. And protrudes in a direction substantially parallel to the rotation axis of the rotating body 42. The plurality of super-hard outer blades 14 protruding from the outer peripheral portion of the rotating body 42 of the present embodiment are inclined in the direction of rotation A toward the distal end side, as in the embodiment of FIG. Since it is fixed at a predetermined interval so as to protrude from the outer peripheral portion of the rotating body 42, a positive rake angle θ _S is formed on the side surface of the super-hard outer peripheral blade 14 on the rotation direction A side. 1
The same effects as those of the rotary grinding tool 10 of the embodiment shown in FIG. In addition to this, the super-hard outer peripheral blade 1 of the present embodiment is also provided.
Since the fourth cutting edge 18 is located in one plane,
Grinding work efficiency for surface grinding is improved.

While the embodiment of the present invention has been described with reference to the drawings, the present invention can be applied to other embodiments.

For example, in the rotary grinding tools 10, 20, 30, and 40 of the above-described embodiment, the super hard outer peripheral blades 14, 22
The rotation trajectories of the cutting edges 18 and 26 have a cylindrical surface or a flat surface, but may have a curved shape, for example, as a processing surface of a general-purpose grindstone.

Further, the super hard outer peripheral blade 14 of the aforementioned embodiment,
22 has a rectangular column shape with a rectangular cross section, but may have a longitudinal shape such as a round cross section, an elliptical cross section, and a triangular cross section. In short, it suffices that the cross-sectional shape of the super-hard outer peripheral blades 14 and 22 does not change even if at least the tip ends thereof are worn.

Further, the super hard outer peripheral blade 14 of the above-described embodiment,
The cutting edges 18 and 26 of the rotary grinding tools 10 and 20
Is set so as to be substantially perpendicular to the rotation direction A, that is, the grinding direction of the super-hard outer peripheral blades 14 and 22, but it does not necessarily have to be perpendicular.

Further, the super hard outer peripheral blade 14 of the above-described embodiment,
At 22, the wear resistance direction T of the tip end face 16 is substantially parallel to the rotation direction A of the rotary grinding tools 10 and 20, that is, the grinding direction of the super hard outer peripheral blades 14 and 22,
It does not necessarily have to be substantially parallel.

The above description is merely an embodiment of the present invention, and the present invention can be variously modified without departing from the gist of the present invention.

[Brief description of the drawings]

FIG. 1 is a partially cutaway front view for explaining a rotary grinding tool according to one embodiment of the present invention.

FIG. 2 is a side view of the rotary grinding tool of FIG.

FIG. 3 is a perspective view showing a shape of a super hard outer peripheral blade used for the rotary grinding tool of FIG. 1;

FIG. 4 is a partially cutaway front view for explaining a rotary grinding tool according to another embodiment of the present invention, and is a view corresponding to FIG. 1;

FIG. 5 is a front view partially cut away for explaining a rotary grinding tool according to another embodiment of the present invention, and is a view corresponding to FIG. 1;

FIG. 6 is a side view of the rotary grinding tool of FIG. 5;

FIG. 7 is a front view illustrating a rotary grinding tool according to another embodiment of the present invention.

FIG. 8 is a partially cutaway side view for explaining the rotary grinding tool of FIG. 7;

[Explanation of symbols]

10, 20, 30, 40: rotary grinding tool 12, 32, 42: rotating body 14, 22: super-hard peripheral blade (super-hard member composed of single crystal or polycrystalline diamond or CBN)

Claims (2)

[Claims] 1. A plurality of columnar super-hard members made of diamond or CBN are fixed at predetermined intervals so as to protrude from an outer peripheral portion of a rotating body in a state of being inclined so as to move in a direction of rotation toward a tip end side. A rotary grinding tool having a super hard outer peripheral edge characterized by the following. 2. The rotary grinding tool having an ultra-hard outer peripheral edge according to claim 1, wherein the columnar super-hard member has a tip surface having a positive clearance angle.